This invention relates to exercise equipment and in particular to a type of such equipment which is capable of being gripped by a user and subsequently squeezed in succession to effect a desired conditioning of the muscles involved in squeezing of the device by providing a nonvarying means of resistance.
In the hand exercise equipment field, it is known to use an exerciser that is in essence a gripper which employs a torsion spring to generate a desired resistance against which the operator exercises. An example of such an arrangement is disclosed in U.S. Pat. No. 4,623,141 issued to Salvino on Nov. 18, 1986 and entitled HAND HELD ARM AND HAND MUSCLE BUILDER. In this patent, it is disclosed to employ a coiled spring the ends thereof being integrally and respectively formed with handles each of which is in turn shaped to readily conform to the users grip. However, a number of drawbacks are associated with using hand grippers of this type. The first of these is that the resistant force (F) is not a constant force, but is one related to displacement as defined by the following equation: EQU F=KX,
wherein, K is the spring constant and X is the deflection of the spring measured from a given at rest position.
Thus, is it apparent that with the increase of deflection of the spring, the resistant force linearly increases. This results in the uneven exercising of muscles used by the hand during a work out because in the muscle building process the smaller fingers which are not sufficiently strong to counter the linearly increasing force generated by the spring do not work, but defer to the larger more strong muscles in the involved hand. Thus, all the muscles in every finger of the hand being exercised are not exercised evenly or continuously thereby resulting in the loss of the effectiveness of the exercise equipment.
It is therefore an object of the present invention to provide a hand exerciser wherein the exerciser includes means for presenting a nonvarying resistance force to the user when squeezing it.
A further object of the present invention is to provide a gripper of the aforementioned type which is compact and self-contained while nevertheless providing the desired uniform resistance force.
Other objects and advantages of the invention will become apparent from the following description and the appended claims.